Internet communities of Korea and China appear to be staging online wars as the latter boycotts Lotte products over the retail giant's recent decision to offer land for a U.S. anti-missile Terminal High Altitude Area Defense (THAAD) battery here.

On Thursday afternoon, Lotte Duty Free's official website in every language was attacked by unidentified Chinese hackers and was restored a few hours later. Lotte Group's official Chinese website (lotte.cn) has been inaccessible since Tuesday as well, due to an apparent cyberattack by unidentified Chinese hackers.

Koreans have begun to condemn their neighbor's retaliatory measures, demanding Korean consumers boycott products made in China as well.

"China has a large territory, but the people are narrow-minded," a Korean internet user said. "Lotte and other Korean companies should leave China, after dismissing thousands of Chinese employees."

Some people said China still seems to regard Korea as a "tributary state," pointing out Beijing did not take similar measures against the United States and Japan in past cases.

Koreans are becoming more and more angry as Chinese people began an online boycott of Lotte affiliates operating there, after Korea's fifth-largest conglomerate signed a land swap deal with the Ministry of National Defense, Tuesday.

That day, CEO Chen Ou of JuMei.com, one of China's leading online cosmetic shopping platforms, wrote on Weibo, "We won't display Lotte products at our promotional event for our seventh anniversary, Wednesday. We won't sell them from now on."

More than 130,000 internet users have "liked" the message posted on the country's most popular local social media as of Thursday morning.

Several Chinese food companies, such as Wei Long and Ta Dao, announced online that they would not supply their products to Lotte Mart in China anymore.

Also, Chinese consumers held rallies at the Korean Consulate in Qingdao and a Lotte Mart outlet in Beijing, both of which have gone viral on Weibo. The protesters held red placards that read, "Lotte declared war against China. Lotte should leave China right now."

A Chinese internet user wrote on Weibo, "Lotte offered the land to be patriotic. Then Chinese people have no reason not to be patriots."

In addition, China's state-run news outlets are encouraging consumers to deepen the Lotte boycott. "Chinese consumers should become the main force in teaching Seoul a lesson, punishing the nation through the power of the market," the Global Times said in an editorial, Wednesday.

China has strongly opposed the THAAD deployment, saying it could monitor airborne objects not only in North Korea but also in China.

A Lotte Group spokesman said the company has yet to take any measures, although it is aware of the rapidly spreading online boycott in China. The group operates a total of 120 business sites in China, employing 26,000 people in the world's most populous country.